Partition and partition chamber for rotary engines

ABSTRACT

A device and method for selectively maintaining pressure in a toroidal cylinder having an internal wall and a piston moving in the toroidal cylinder, the device including at least one partition plate pivotally mounted in the internal wall for selective sealing engagement of the internal wall of the cylinder, whereby a selected portion of the cylinder between the partition plate and the piston is selectively maintained at high pressure.

FIELD OF THE INVENTION

The present invention relates to rotary compressors and internal combustion engines and, in particular, to rotary internal combustion engines with split cycle and coupled cylinders.

BACKGROUND OF THE INVENTION

In an effort to improve the basic efficiency of a rotary type engine, it has been proposed to configure first and second cylinders utilizing a common rotor deployed within a single toroidal chamber with all four strokes of the four stroke cycle being performed simultaneously, with the intake and compression strokes performed in the first cylinder simultaneous to combustion and the expansion strokes of a different cycle being performed in the second cylinder. Such a coupled cylinder engine, entitled “Internal Combustion Engine with Coupled Cylinders” was disclosed in International Application Number PCT/IL2005/000855 filed on 9 Aug. 2005 and published on Feb. 16, 2006 as International Publication. No. WO 2006/0163582.

One of the key elements of a rotary engine described in the above mentioned patent application is a partition wall that seals the cylinder's cross-section and allows free movement of lobe-pistons along the toroidal cylinder, without compromising its sealing. Partition walls, in the form of flat, rectangular plates moving reciprocally in a radial direction and forced by the combined action of the rotor's profile and external springs, were presented in Patent Publication WO 2008/0770232. However, the use of reciprocating vanes or partitions has a number of difficulties: the high pressure generated during ignition of a charge forces the reciprocating plate towards its guides and can impede its reciprocal movement; spring-based devices are inertial and have limited durability; hermetic sealing of the spring shaft is complicated, etc.

Accordingly, there is a long felt need for a toroidal cylinder with more reliable partition walls, and it would be very desirable to incorporate such a cylinder into a more efficient rotary engine.

SUMMARY OF THE INVENTION

The present invention relates to a pivotal partition and a partition chamber for use in a toroidal cylinder defined between a housing and a rotor, in general, and in particular, in a rotary engine. The partition is pivotally mounted in the housing and pivots within the volume defined between a housing and a rotor, when pushed by a lobe-piston on the rotor, or in response to pressure gradients in the toroidal cylinder.

There is provided, according to the present invention, a device for selectively maintaining pressure in a toroidal cylinder having an internal wall and a piston moving in the toroidal cylinder, the device including at least one partition plate pivotally mounted in the internal wall for selective sealing engagement of the internal wall of the cylinder, whereby a selected portion of the cylinder between the partition plate and the piston is selectively maintained at high pressure.

According to one embodiment of the invention, the device further includes a partition chamber mounted in the internal wall, wherein the partition plate is pivotally mounted about a pivot axis in a wall of the partition chamber.

There is also provided, according to the invention, a toroidal cylinder for a rotary compressor or engine, the toroidal cylinder including a rotor defining at least one lobe piston, a housing mounted about the rotor, the toroidal cylinder having internal walls defined between the rotor and the housing, at least one partition plate pivotally mounted in the housing for selective sealing engagement of the internal walls of the toroidal cylinder, the lobe piston being disposed in the toroidal cylinder so as to pivot the partition plate during rotation of the rotor, whereby a selected portion of the cylinder between the partition plate and the lobe piston is selectively maintained at high pressure.

There is further provided, according to the invention, a method for selectively maintaining pressure in a selected portion of a toroidal cylinder formed between a housing and a rotor having at least one lobe piston protruding into the cylinder, the method including pivotally mounting a partition plate in the toroidal cylinder, rotating the rotor by means of differential pressure in the cylinder, selectively sealing the cylinder by the partition plate, thereby maintaining high pressure in a portion of the cylinder between the partition plate and the lobe piston, and pivoting the partition plate by the lobe piston as the rotor rotates, until the piston passes the partition.

According to one embodiment of the invention, the step of pivotally mounting includes mounting a partition chamber in the housing and pivotally mounting the partition plate in the partition chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further understood and appreciated from the following detailed description taken in conjunction with the drawings in which:

FIG. 1 a is a schematic side-sectional illustration of a pivotal partition in a rotary engine, constructed and operative in accordance with one embodiment of the present invention;

FIG. 1 b is a schematic cross-sectional illustration of one of the cylinders of the rotary engine of FIG. 1 a, taken through line A-A,

FIG. 2 is a schematic illustration of a pivotal partition during passage of a piston, according to one embodiment of the invention;

FIG. 3 is a schematic illustration of a pivotal partition during passage of a front-cut piston, according to another embodiment of the invention;

FIGS. 4 a, 4 b and 4 c are schematic views of a partition chamber and toroidal cylinder, according to one embodiment of the invention, in longitudinal cross-section, transverse cross-section along the plane A-A, and a general view, respectively;

FIG. 5 is a schematic view of an intake-compression cylinder with a pivotal partition chamber according to the invention;

FIG. 6 is a schematic view of an ignition-expansion-exhaust cylinder with a pivotal partition chamber, according to the invention;

FIG. 7 is a schematic top view of a partition chamber with two pivotal partitions;

FIG. 8 is a schematic illustration of a rotary engine including cylinders with pivotal partitions according to the invention;

FIG. 9 is a schematic illustration of a partition according to one embodiment of the invention, composed of a plurality of layers; and

FIG. 10 is a schematic illustration of an eccentrically mounted partition plate.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to design and operation of devices for selectively maintaining pressure including a toroidal cylinder defined by the internal walls of a housing and a rotor, and at least one piston protruding from the rotor and rotating within the toroidal cylinder, characterized by at least one partition plate pivotally mounted in the housing for selective sealing engagement with the internal walls of the cylinder. In this way, a portion of the cylinder between the partition plate and the piston is selectively maintained at high pressure. Typically, the device includes a rotor defining at least one lobe piston, a stator mounted adjacent the rotor and defining between them a toroidal cylinder, at least one partition plate pivotally mounted in the stator for selectively sealingly engaging internal walls of the toroidal cylinder. The lobe piston is disposed in the toroidal cylinder so as to pivot the partition plate during rotation of the rotor.

The present invention is particularly useful for internal combustion rotary engines, among them engines with split cycle and coupled toroidal cylinders, where the first cylinder performs intake and compression strokes at the same time as the second cylinder performs combustion-expansion and exhaust strokes. In particular, the invention presents principles of design and operation of a pivotal sealing partition and a partition chamber in the stator that provides sealing of the toroidal cylinder cross-section and allows passage of pistons and rotation of the engine's rotor.

Operation of the partition is based on the pressure gradients generated in the engine during its cycle. Thus, the partition operates autonomously and can be used without springs or other auxiliary driving mechanisms. Alternatively, the partition cycle can be regulated by an external mechanism to achieve better efficiency and a wider operating range of the engine. The use of a chamber to house the pivotal partition allows construction of engines with toroidal cylinders having a variety of cross-sections, including rectangular, elliptical and circular.

FIGS. 1 a and 1 b are schematic side-sectional and cross-sectional views, respectively of a pivotal partition in one cylinder of a rotary engine, constructed and operative in accordance with one embodiment of the present invention.

In this embodiment, a rotor (114) and a housing or stator (110) define between them a toroidal cylinder (112). A partition (102), here illustrated in the form of a bent rectangular plate, is pivotally mounted on an axis (104) that allows its pivotal movement. Alternatively, partition (102) be straight (i.e., not bent). In this embodiment, the partition axis (104) is parallel to the rotor axis (not shown). The length of the pivotal partition, defined as the distance between its axis and the sealing edge tip (106), is larger than the respective dimension of the cylinder's cross-section. Therefore, the orientation of the partition is constrained between its uppermost position, when the partition is forced into a nesting pocket (108) in the housing (110), and its lowest (down) position, when it is forced towards the floor of the toroidal cylinder (112) and engages an edge of the rotor (114).

The rotor includes one or more lobe portions (116), which act like pistons in conventional engines (called herein lobe-pistons). As the rotor (114) rotates in the direction indicated by the arrow, partition plate (102) pivots about pivot axis (104) and the tip (106) of the partition slides along the incoming front edge (118) of the lobe piston (116) until the partition reaches its uppermost position, nested in pocket (108), allowing the piston to pass beneath it. The partition then slides down along the rear-side profile or contour (119) towards its lowest position. As indicated for the position illustrated in FIG. 1 a, a low pressure region is formed between the front or leading edge (118) of the lobe piston and the partition plate, while a high pressure region is formed behind the partition plate (102) (as defined by the direction of the rotor). This high pressure urges the partition plate (102) into contact with the disk of the rotor or the lobe piston at all times.

In the embodiment of FIG. 1 a, the cross section of the toroidal cylinder and, therefore, of the partition plate, is rectangular, as best seen in FIG. 1 b. For a rectangular toroidal cylinder, the rotor is equipped with a rectangular shaped lobe-piston, preferably having a flat-cut profile or contour parallel to the shaft axis. The partition is equipped with side, corner and tip sealing elements (not shown) that provide hermetic sealing of the rectangular cylinder.

Referring now to FIG. 2, there is shown a schematic view of a curved pivotal partition (202) during passage of a lobe piston (216). As can be seen, pivotal partition (202) is mounted in a housing (210) about a pivot axis (204).The tip (206) of the pivotal partition (202) engages the forward edge (218) of the lobe piston (216) as the rotor (214) rotates in the direction of the arrow and the lobe piston (216) on the rotor (214) moves through the toroidal cylinder (212).

In this embodiment, the profile or outline of the lobe piston is designed to provide constant contact between the piston surface and the partition. The tip of the partition, which sealingly engages the piston, must make a proper (variable) attack angle with the surface it contacts: the peripheral edge of the rotor disk, the front and the rear edges of the lobe-pistons. The pivotal partition has, therefore, been bent to the required curvature.

Contrary to conventional internal combustion engines, where all four strokes of the cycle take place at the same location, different strokes are performed at different locations in the rotary engine described in this invention. As a result, the pressure gradient direction is always constant at any stage of operation, in both the intake-compression cylinder and in the combustion-exhaust cylinder. High pressure forces the partition towards the piston and provides sealing of the cylinder, whereas movement of the rotor pushes the sliding edge of the pivotal partition and opens the passage for the piston.

The location and pivot chirality of the pivotal partition depend on the type of cylinder. In an intake-compressor cylinder, a high pressure region is created between the partition and the front edge of the propagating piston. For a rotor rotating in the clockwise direction, the incoming piston causes the partition to pivot and pushes the partition tip upward, and the partition pivots in the clockwise direction about its axis. The high pressure region in the combustion-exhaust cylinder is created between the partition and the outgoing rear edge of the lobe-piston. In this case, the incoming piston forces the partition to turn counter-clockwise, for a rotor rotating in the clockwise direction. This is the case illustrated in FIGS. 1 a, 2 and 3.

The length of the segment of the rotor occupied by a lobe-piston (i.e., the length of the base of the piston) may be important for certain embodiments. A piston of reduced length can be used in the combustion-exhaust cylinder, since sealing contact between a tip of the pivotal partition and the front edge of the incoming piston might not be required for its operation, but only sealing contact between the tip of the partition and the rear edge of the piston. Accordingly, a flat partition may be utilized in this case. Similarly, a piston of reduced length can be used in the intake-compression cylinder, since sealing contact between a tip of the pivotal partition and the rear edge of the incoming piston might not be required for its operation, but only sealing contact between the tip of the partition and the front edge of the piston. An example of this form of a piston and embodiment of the partition operation is shown schematically in FIG. 3, a schematic view of a pivotal partition (302) during a passage of a front-cut piston (316) in a combustion-exhaust cylinder.

As can be seen, the front edge (318) of the piston (316) is cut sharp and has an apex (317). The partition (302) is pushed by the front edge (317) of the piston with no contact between the partition's tip (306) and the front edge (318) of the piston. It will be appreciated that the piston fills the entire cross-section of the cylinder when passing below the partition, the partition being in its nesting pocket (308). However, this bending of the plate is not necessary and a straight plate can be utilized, if desired. When the apex (317) of the piston passes the partition tip (306), the tip slides along the rear edge of the piston and the partition pivots downwards towards its downward closed position.

In the embodiments described above, a rectangular pivotal partition provides a sealing solution for an engine with a rectangular toroidal cylinder. For engines with toroidal cylinders and respective lobe-pistons having non-rectangular cross-sections, e.g., circular, elliptical or rectangular with rounded corners, a partition chamber is built into the housing and the partition plate is pivotally mounted inside the partition chamber. FIGS. 4 a, 4 b and 4 c are schematic illustrations of a partition chamber (400) in a toroidal cylinder (401) with a circular cross-section, in longitudinal cross-section, transverse cross-section along the plane A-A, and enlarged perspective view, respectively, by way of example.

Partition chamber (400) includes a front or entrance wall (404), a rear or exit wall (406), side walls (408), a top cover (410) and a bottom section (411). The side walls (408) may be parallel, flat walls, as illustrated. Alternatively, the side walls may be rounded and cut in such a form that the side edges of the pivoting partition remain in sealing contact with the side walls of the chamber at any position. The bottom section (411) has a slot (412) along the cylinder fitted to the size of the rotor's disk (414). Slot (412) extends into apertures (418) through front wall (404) and rear wall (406) fitted to the form of lobe pistons (416) to permit the lobe pistons to pass through the partition chamber.

The chamber is mounted in the housing and occupies a section of the toroidal cylinder. Chamber (400) accommodates a pivotal partition (402). The partition within the partition chamber can have a non-rectangular shape, fitted to the profile of the side walls of the chamber. The bottom edge of the plate must be parallel to the partition axis but the side edges can be rounded. It will be appreciated that, when the pistons have a flat-cut profile parallel to the shaft axis, the bottom edge must fit this profile.

The transverse cross-section of the partition chamber as illustrated in FIG. 4 b has a rectangular profile, although this profile will change if the side walls are not flat and parallel walls. The distance between the walls corresponds to the width of the pivotal partition (402). The partition in its down position is urged against the bottom of the chamber and the flat edge of the rotor disk and seals the chamber.

It will be appreciated that the design of the toroidal cylinder of the intake-compression and the ignition-exhaust cylinders may be different, due to the optimization of each cylinder. Similarly, the profile of the piston is also defined according to the shape of the toroidal cylinder. Accordingly, the profiles of the entrance and exit walls of the partition chambers in the two cylinders may also vary, so as to correspond to the shape of the cylinder. In particular, the partition chamber and/or the partition plate are mounted at an orientation rotated by 180 degrees relative to one another in the intake-compression cylinder as compared to the ignition-exhaust cylinder.

FIG. 5 is a schematic view of an intake-compression cylinder with a pivotal partition chamber (500), according to one embodiment of the invention. A toroidal cylinder (512) is formed between the housing (510) of the intake-compression cylinder and the rotor (514). At least one lobe piston (516) is provided on rotor (514). Partition chamber (500) is mounted in housing (510) and includes a front or entrance wall (504), a rear or exit wall (506), side walls and a bottom section with a slot for the rotor and apertures for the lobe pistons, substantially as described above with respect to FIG. 4 a.

A pivotal partition (502) is mounted in partition chamber (500) with its pivot axis (501) adjacent rear wall (506) of the chamber. A high pressure region H in the intake-compression cylinder is created between the front (518) of the piston (516) and the partition (502).

The rear face (519) of the partition (502) in its down position is pressed towards the rear wall (506) when lobe-piston (516) is outside the partition chamber. The profile or outline of the exit wall is fitted to the profile of the partition. When the front edge of the incoming lobe-piston penetrates the partition chamber through the aperture in the entrance wall (504), the partition slides along the incoming piston front edge and pivots upwards, thus separating the partition chamber into two parts: above and below the partition. The profile of the entrance wall (504) has a curvature with a radius equal to the length of the partition. The tip of the pivotal partition slides along the entrance wall, pushed up by the propagating front edge of the lobe, and maintains sealing contact both with the entrance wall and with the piston. The penetrating lobe-piston fills the lower part of the entrance wall aperture and pushes the compressed charge (i.e., gases with or without combustible material) above the pivotal partition into the partition chamber.

When the desired compression of the charge is achieved, an entrance port into a charge transfer channel (518), located in the upper part of the partition chamber, is opened by a control mechanism (not shown) and the compressed charge is pushed into the transfer channel by the propagating piston (516) and by the partition as it pivots upward. The charge transfer is terminated when the partition reaches its uppermost position and the transfer channel is closed. At this moment, the apex of the piston lobe slips away behind the partition and through the aperture in the rear wall (506) of the chamber. A low pressure region L is created below the partition behind the outgoing piston. The partition begins to pivot downwards, pushed from above by the portion of the charge that remains in the entrance section of the transfer channel. The partition tip slides along the rear edge of the piston lobe until it reaches its down position and seals the cylinder. Thus, the piston passage stage is completed and the cylinder is divided to two sections, where the intake of a new charge takes place through an intake aperture (520) behind the partition, while compression of the previously taken charge is performed in front of the partition.

Although the structure of the partition chamber in the combustion-exhaust cylinder is similar to that of the intake-compression chamber, its orientation is different. FIG. 6 is a schematic view of an ignition-expansion-exhaust cylinder (600) with a pivotal partition chamber, according to one embodiment of the invention. Ignition-expansion-exhaust cylinder (600) includes a toroidal cylinder (612) formed between the housing (610) of the combustion-exhaust cylinder and the rotor (614) of the engine. A lobe piston (616) is provided on rotor (614). Partition chamber (600) is mounted in housing (610) and includes a front or entrance wall (604), a rear or exit wall (606), side walls and a bottom section with a slot for the rotor and apertures for the lobe pistons, substantially as described above with respect to FIG. 4 a.

A high pressure region H in the combustion-exhaust cylinder is created between the rear side (619) of the piston (616) and the partition (602). The partition, in its down position, is pressed towards the entrance wall (604) when the lobe-piston is outside the partition chamber. The profile of the entrance wall is fitted to the profile of the partition. The profile of the exit wall has a curvature with a radius equal to the length of the partition. The tip of the pivotal partition slides along the exit wall, pivoted upwards by the propagating front edge (617) of the lobe piston, and maintains sealing contact both with the exit wall and the piston.

An outlet port of the charge transfer channel (618) and an ignition device (622) are located in the upper part of the partition chamber. Other engine parts can also be located in the partition chamber. When the pivotal partition passes its upper position, the charge transfer channel (618) is opened and the compressed charge from the compression cylinder is accumulated between the chamber's top cover, the pivotal partition and the rear side of the lobe-piston. Here the charge is ignited. Combustion of the charge against the piston causes the rotor to rotate. An open exhaust aperture (620) is formed in a wall of toroidal cylinder (612) in front of the propagating lobe-piston adjacent to the partition chamber. Thus, there is high pressure behind the piston and low pressure in front of the piston where the exhaust aperture is positioned. As the piston (616) passes exhaust aperture (620), the low pressure exhaust gases escape through the exhaust aperture (620).

The structure of the partition chambers described above can be implemented both for the intake-compression and for the ignition-exhaust cylinders, when the partition axis is parallel to the rotor's rotation shaft and the partition chamber cover extends beyond the external perimeter of the toroidal cylinders. An alternative embodiment of the partition chamber contains a partition mounted on its axis where the partition axis is parallel to the plane of the toroidal cylinder and perpendicular to the rotor shaft axis. In this case, the contour or profile of the lobe-pistons is cut in such a way that the pivotal partition slides along the cut front and rear edges of the piston while remaining in sealing contact at every cross-section point (or at the selected edges only).

Another embodiment of the partition chamber contains a partition mounted on its axis when the partition axis is at an arbitrary angle between zero and 180° relative to the rotor shaft axis. Here, too, the profile of the lobe-pistons is cut in such a way that the pivotal partition slides along the cut front and rear edges of the piston while remaining in sealing contact at every cross-section point (or at selected edges only).

Yet another embodiment of a partition chamber according to the invention is shown schematically in FIG. 7, a schematic top view of a partition chamber (700) with a pivotal partition split into two partitions (702). According to this embodiment, the chamber is mounted in the housing (712) of, for example, an intake-compression toroidal cylinder, and occupies a section of the toroidal cylinder. Partition chamber (700) serves to accommodate two pivotal partitions (702) at two sides of the chamber, each pivoting about its own pivot axis (704). The chamber has an entrance or front wall (706), an exit or rear wall (708), a flat bottom wall, a flat top cover (710) and two side covers. The lobe pistons (714) of this embodiment are shaped to pivot both partitions (702) simultaneously. Each lobe piston (714) has a front edge profile (716) and a rear edge profile (718), which may be the same or may be different from one another. The entrance (706) and exit (708) walls have apertures fitted to the form of the lobe-pistons (714) of the rotor (720): rectangular, round or elliptical for respective cross-sections of the toroidal cylinder. The transverse cross-section of the partition chamber may have a rectangular or other profile, as described above with respect to the single partition chambers, its height corresponding to the width of the pivotal partition. The partitions in their down closed position, shown in FIG. 7, seal the chamber. An intake aperture (722) is provided for the intake of a new charge.

Operation of this embodiment is substantially the same as that of FIG. 5, except that the two portions of the split partition slide along opposite sides of the piston and open as mirror images of one another. The profiles of the entrance and exit walls are different in the intake-compression cylinder and in the ignition-exhaust cylinder, similar to the case of a single partition in the partition chamber discussed above.

Although operation of the pivotal partition is based on pressure gradients constantly present in the engine and does not require springs or other driving mechanisms, there are certain embodiments in which control of the pivotal partition might be useful. Thus, one embodiment of the engine includes an auxiliary mechanism that can drive and control the position and timing of the partition cycle and/or act as a latch mechanism that can latch the partition in a constant and/or temporary open position. One example of such an auxiliary mechanism (800) for a rotary engine (810) of the present invention is shown in FIG. 8, which includes at least one cam, here shown as a plurality of interconnected gear wheels (802) coupled to the axis (814) of the partition, synchronized with the angular position of the rotor relative to the housing, that drives or assists in pivoting the partition. . Alternatively, any other suitable mechanism can be utilized. With the help of the driving mechanism, the partition (812) can pivot about its axis (814) with its tip being forced into contact with the propagating piston-lobe or being driven by the driving mechanism without direct contact with the propagating piston-lobe.

A number of additional functions and properties can optionally be provided. Cooling of the partition can be provided, if desired. Cooling can be accomplished by providing a special channel within the partition body and pumping a coolant into it, for example, through the partition axis.

The partition faces, in particular in the combustion cylinder, can be covered by heat resistant material to withstand the high combustion temperatures.

These mechanisms can be combined in a partition (900), illustrated schematically in FIG. 9 a, composed of at least three layers: a high heat resistive layer (902) facing towards the partition chamber (i.e., facing the combustion), an internal layer (904) having channels (906) for a coolant and/or lubrication liquid; and an external layer (908) on the surface facing outside the partition chamber when the partition is in its closed downward position. The internal layer serves for cooling of the partition by a selected coolant, the coolant being supplied via the partition axis, and lubrication of the sealing elements along the perimeter of the partition and/or supply of the lubricant into the cylinder volume.

It will be appreciated that several of the partition chambers described above have inlet and/or outlet ports for compressed air/charge transfer, an ignition device, sensors or any other additional elements located in the top (or side) cover. All or some of these elements penetrate into the internal volume of the chamber. According to one embodiment of the invention, illustrated schematically in FIG. 9 b, the pivotal partition (920) is formed with an external profile to accommodate the profile of the cover (930) and having recesses (922) to fit the protruding elements (932) when the partition is in its uppermost (or outermost) position pressed towards the cover.

The walls of the partition chamber preferably are cooled by an external coolant jacket (not shown), together with the rest of the toroidal cylinder.

Lubrication of the piston may be performed through the entrance and exit apertures in the entrance and exit walls of the partition chamber during passage of the piston through the respective walls. In particular, the piston lobe perimeter can be lubricated when leaving the partition chamber via the exit wall and the lubricant being wiped off during passage through the entrance wall of the partition chamber prior to entering the high temperature combustion region.

In the embodiments described above, the partition plate seals against the wall of the partition chamber or against the walls of the toroidal cylinder. According to an alternative embodiment of the invention, an additional sealing element (not shown) is mounted on the internal side of the exit wall of the compressor partition chamber and on the internal side of the entrance wall of the combustion partition chamber. This additional sealing element surrounds the aperture and protrudes into the partition chamber. When the pivotal partition is in its closed downward position, it is pressed towards the respective entrance/exit walls. At this stage, the additional sealing element seals the gap between the face of the partition and the respective wall.

According to a further embodiment, the pivotal partition is mounted eccentrically relative to (i.e., not in registration with) its pivot axis. FIG. 10 shows an eccentrically mounted partition plate (950). In this case, the partition axis (952) is mounted outside of the partition chamber (954), with only the partition itself inside the chamber. This type of mounting provides easier access to the partition axis, for example, for easier cooling of the axis.

It should also be mentioned that the pivotal partition disclosed in this invention, operated by pressure gradients, is also applicable for other types of rotary engines, including engines with external combustion chambers. The invention can also be used for a stand-alone rotary compressor. The intake-compressor cylinder, by itself, is a compressor.)

While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made. It will further be appreciated that the invention is not limited to what has been described hereinabove merely by way of example. Rather, the invention is limited solely by the claims which follow. 

1. A device for selectively maintaining pressure in a toroidal cylinder having an internal wall and a piston moving in the toroidal cylinder, the device comprising: at least one partition plate pivotally mounted in the internal wall for selective sealing engagement of the internal wall of the cylinder, whereby a selected portion of the cylinder between the partition plate and the piston is selectively maintained at high pressure.
 2. The device according to claim 1, further comprising a partition chamber mounted in said internal wall, wherein said partition plate is pivotally mounted about a pivot axis in a wall of said partition chamber.
 3. The device according to claim 1, further comprising a partition chamber mounted in said internal wall, wherein said partition plate is eccentrically mounted in said partition chamber about a pivot axis outside said partition chamber.
 4. A toroidal cylinder for a rotary compressor or engine, the toroidal cylinder including: a rotor defining at least one lobe piston; a housing mounted about the rotor; the toroidal cylinder having internal walls defined between said rotor and said housing; at least one partition plate pivotally mounted in said housing for selective sealing engagement of said internal walls of the toroidal cylinder; said lobe piston being disposed in said toroidal cylinder so as to pivot said partition plate during rotation of said rotor; whereby a selected portion of the cylinder between the partition plate and the lobe piston is selectively maintained at high pressure.
 5. The toroidal cylinder according to claim 4, wherein said partition plate is mounted for selective seating in a recess in said housing.
 6. The toroidal cylinder according to claim 4, further comprising an external mechanism for pivoting said partition plate synchronized with said rotor.
 7. The toroidal cylinder according to claim 4, wherein said partition plate includes an external layer of heat resistant material.
 8. The toroidal cylinder according to claim 4, wherein said partition plate includes a layer of fluid channels for cooling and/or lubrication fluid.
 9. The toroidal cylinder according to claim 4, wherein an outer surface of said partition plate defines at least one recess for receiving engine parts protruding from said housing into said toroidal cylinder.
 10. The toroidal cylinder according to claim 4, further comprising a partition chamber mounted in said housing, wherein said partition plate is pivotally mounted about a pivot axis in a wall of said partition chamber.
 11. The toroidal cylinder according to claim 4, further comprising a partition chamber mounted in said housing, wherein said partition plate is eccentrically mounted in said partition chamber about a pivot axis outside said partition chamber.
 12. The toroidal cylinder according to claim 10, wherein said partition chamber is mounted in said housing and includes: an entrance wall and an exit wall, each defining apertures for passage of the lobe pistons; side walls; and a bottom section with a slot for the rotor.
 13. A rotary compressor comprising: a toroidal cylinder defined between a housing and a rotor; a lobe piston defined on said rotor and protruding into said toroidal cylinder; an intake aperture into said toroidal cylinder; a compressed charge transfer channel; and a partition plate, having a profile complementary to a profile of said toroidal cylinder, for selective sealing engagement of the cylinder, pivotally mounted in said housing before said intake aperture and behind said a compressed charge transfer channel, relative to a direction of rotation of said rotor.
 14. The rotary compressor of claim 13, further comprising: a second toroidal cylinder defined between a second housing and a second rotor, said second rotor being co-axial with said first rotor and coupled for synchronized rotation therewith, thereby forming a rotary engine; at least one lobe piston protruding from said second rotor into said second toroidal cylinder; a compressed charge inlet in said second toroidal cylinder coupled to said compressed charge transfer channel; an igniter for combustion of a compressed charge from said compressed charge inlet; an exhaust aperture for release of exhaust gases; and a second partition plate having a profile complementary to a profile of the second cylinder for sealing engagement of the second cylinder, pivotally mounted at an orientation rotated by 180 degrees relative to said first partition plate, behind said exhaust aperture and before said igniter, relative to a direction of rotation of said rotor.
 15. A method for selectively maintaining pressure in a selected portion of a toroidal cylinder formed between a housing and a rotor having at least one lobe piston protruding into the cylinder, the method comprising: pivotally mounting a partition plate in the toroidal cylinder; rotating the rotor by means of differential pressure in the cylinder; selectively sealing the cylinder by the partition plate, thereby maintaining high pressure in a portion of the cylinder between the partition plate and the lobe piston; and pivoting said partition plate by the lobe piston as the rotor rotates, until the piston passes the partition.
 16. The method according to claim 15, wherein said step of pivotally mounting includes: mounting a partition chamber in said housing; and pivotally mounting said partition plate in said partition chamber.
 17. The method according to claim 16, wherein said step of pivotally mounting includes pivotally mounting said partition plate in a wall of said partition chamber.
 18. The method according to claim 16, wherein said step of pivotally mounting includes eccentrically mounting said partition plate in said partition chamber about a pivot axis outside said partition chamber.
 19. The method according to claim 15, wherein said step of selectively sealing is implemented by an external mechanism coupled to said partition plate and synchronized with said rotor.
 20. The method according to claim 15, wherein said step of selectively sealing is implemented by said pressure differential in said cylinder. 